1. Field of the Invention
The present invention relates to a paper cassette for an electrophotographic apparatus and, more specifically, to a paper cassette having an improved fingering device.
2. Background Art
An image formation apparatus (e.g., a printer, scanner, facsimile or copier) must often accommodate printable mediums having a thickness or dimensions different from that of standard paper. Envelopes, postcards, transparencies, labels and resume paper are just a few examples of the different printable mediums that a sheet feeder must accommodate. A sheet feeder may be constructed to use a tray that supplies paper to a printer. The tray often has an adjustment lever allowing the paper to be moved away from a pickup roller in order to load additional sheets of paper into the tray. After loading additional paper, the adjustment lever is moved in a direction opposite that used for preparing the tray to receive additional paper causing the pickup roller to press against the paper on the tray and then transfer the paper to a transfer roller. Then, the transfer roller transports the sheet of paper to the printer cartridge.
However, when an envelope or a postcard weighing more than 90 g is attempted to be fed into the printer, the pick up roller is often unable to overcome the frictional force exerted by the finger of the paper cassette. This leads to paper jams that can disrupt an efficiently running business.
To overcome this problem some conventional printers require the manual feeding of thick paper into the printer. This results in the consumption of human resources and lowers the printer's efficiency. Another method has been to use a mode conversion lever that could be adjusted to prevent the finger from being operated. Thus, when a user wanted to print on heavy paper, the mode of the paper cassette could be set to prevent the finger from restraining the loading of paper into the printer.
I believe that is may be possible to improve on the contemporary art by providing a paper cassette that has a finger that allows paper to pass by simply pushing against a side plate and that does not require special handling by a user to accommodate thicker and heavier sheets of paper or envelopes.